public class Test4 {

    public static void main(String[] args) {
//        String str1 = "a" + "b" + "c";
//        String str2 = "abc";
//        String str3 = new String("abc");
//        System.out.println(str1 == str2);
//        System.out.println(str2 == str3);
//        System.out.println(str1.hashCode() + "、" + str2.hashCode() + "、" + str3.hashCode());

        Person a = new Person();
        a.age = 10;
        Person b = new Person();
        b.age = 18;
        
        System.out.println(a.age);
    }
}

class Person {
    public int age;
}
